Fix compiling and installing of Scheme modules.

Fix compiling of Scheme modules.  Install .go files to the
standard `site-ccache' directory.

* configure.ac: Substitute `GUILE_EFFECTIVE_VERSION'.
* ssh/Makefile.am (dist_pkgguilesite_DATA): Rename to
  `nobase_dist_pkgguilesite_DATA'.
  (ccachedir): Set Guile ccache path.
  (nobase_nodist_pkgguilesite_DATA): Rename to
  `nobase_dist_ccache_DATA'.
  (guilec_opts): Use absolute pathes.
  (guilec_env): Adjust `LD_LIBRARY_PATH' and `GUILE_LOAD_PATH'.